With the development of the electronic device technology, various electronic devices appear in our works and lives, and numerous kinds of functions bring great convenience into our lives.
Accordingly, there is a need for users to store data, and various storage devices are designed in the industry. As a type of storage device, Solid State Disk (SSD) is becoming popular recently. An SSD device is composed of a control unit and memory units (flash chips). In brief, it is a hard disk made of arrays of solid state electronic memory chips. The specification and definition for its interface, functions, and uses are same as those for a normal hard disk. However, there is an important function in the Flash Transition Layer (FTL) module in the controller of a solid state disk: a logical address used when the hard disk is read by the host system is translated into a physical address in a flash chip on the solid state disk. The FTL module maintains the translation mapping relation from the logical addresses to the physical addresses, and such a translation mapping relation is also known as an L2P table. During operations of a solid state disk, there is one and only one valid L2P table which determines the data space of the solid state disk accessible by a host system.
Because there is only one L2P table, all users may access the data space determined by this table. Therefore, there is a problem that the stored data is not safe. In the prior art, to protect the security and privacy of personal data, encrypting will usually be performed in the software and/or hardware layers of a system.
However, in the process for implementing the technical solutions according to embodiments of the present disclosure, the inventor of the present disclosure realizes that the security level of conventional solutions for protecting data security and privacy by encryption at software and/or hardware layers of a system is not high enough, because such encryption will be cracked at a lower level. Furthermore, the conventional solutions are comparatively complicated in both of the process for encryption and/or decryption and the process for management.